Input: usbtouchscreen - implement runtime power management

This implement USB autosuspend while the device is opened for
devices that do remote wakeup with a fallback to open/close for
those devices that don't. Devices that require the host to
constantly poll them are never autosuspended.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Tested-by: Petr Štetiar <ynezz@true.cz>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 24 insertions, 3 deletions

diff --git a/drivers/input/touchscreen/usbtouchscreen.c b/drivers/input/touchscreen/usbtouchscreen.c
index 9cda660ee7bb..77e671f8f1a4 100644
--- a/drivers/input/touchscreen/usbtouchscreen.c
+++ b/drivers/input/touchscreen/usbtouchscreen.c
@@ -1268,6 +1268,7 @@ static void usbtouch_irq(struct urb *urb)
         usbtouch->type->process_pkt(usbtouch, usbtouch->data, urb->actual_length);
 
 exit:
+        usb_mark_last_busy(interface_to_usbdev(usbtouch->interface));
         retval = usb_submit_urb(urb, GFP_ATOMIC);
         if (retval)
                 err("%s - usb_submit_urb failed with result: %d",
@@ -1277,23 +1278,39 @@ exit:
 static int usbtouch_open(struct input_dev *input)
 {
         struct usbtouch_usb *usbtouch = input_get_drvdata(input);
+        int r;
 
         usbtouch->irq->dev = interface_to_usbdev(usbtouch->interface);
 
+        r = usb_autopm_get_interface(usbtouch->interface) ? -EIO : 0;
+        if (r < 0)
+                goto out;
+
         if (!usbtouch->type->irq_always) {
-                if (usb_submit_urb(usbtouch->irq, GFP_KERNEL))
-                  return -EIO;
+                if (usb_submit_urb(usbtouch->irq, GFP_KERNEL)) {
+                        r = -EIO;
+                        goto out_put;
+                }
         }
 
-        return 0;
+        usbtouch->interface->needs_remote_wakeup = 1;
+out_put:
+        usb_autopm_put_interface(usbtouch->interface);
+out:
+        return r;
 }
 
 static void usbtouch_close(struct input_dev *input)
 {
         struct usbtouch_usb *usbtouch = input_get_drvdata(input);
+        int r;
 
         if (!usbtouch->type->irq_always)
                 usb_kill_urb(usbtouch->irq);
+        r = usb_autopm_get_interface(usbtouch->interface);
+        usbtouch->interface->needs_remote_wakeup = 0;
+        if (!r)
+                usb_autopm_put_interface(usbtouch->interface);
 }
 
 static int usbtouch_suspend
@@ -1457,8 +1474,11 @@ static int usbtouch_probe(struct usb_interface *intf,
         usb_set_intfdata(intf, usbtouch);
 
         if (usbtouch->type->irq_always) {
+                /* this can't fail */
+                usb_autopm_get_interface(intf);
                 err = usb_submit_urb(usbtouch->irq, GFP_KERNEL);
                 if (err) {
+                        usb_autopm_put_interface(intf);
                         err("%s - usb_submit_urb failed with result: %d",
                             __func__, err);
                         goto out_unregister_input;
@@ -1512,6 +1532,7 @@ static struct usb_driver usbtouch_driver = {
         .suspend        = usbtouch_suspend,
         .resume         = usbtouch_resume,
         .id_table       = usbtouch_devices,
+        .supports_autosuspend = 1,
 };
 
 static int __init usbtouch_init(void)